//练习2：实现以个函数ex2，能够使用fp.first获取列表的第一个元素
const fp = require('lodash/fp')
const { Maybe, Container } = require('./support')
let xs =Container.of(['do','ray','me','fa','so','la','ti','do'])

let ex2 = () => {
   return xs.map(fp.first)
}

console.log(ex2()._value)